Control Blasting Activity-METHOD STATEMENT FOR CONTROLLED BLASTING WORK

 METHOD STATEMENT FOR CONTROLLED BLASTING WORK

METHOD STATEMENT FOR CONTROLLED BLASTING WORK

SR. No.	TITLE
1	INTRODUCTION
2	SCOPE OF WORK
3	REFERENCES AND STANDARDS
4	TOOLS / TACKELS AND MACHENIRIES
5	MATERIALS AND SPECATIONS
6	REQUIERD MANPOWER AND RESPONSIABILITY
7	SHORT NOTE ON BLASTING
8	PROCEDURE
9	QUALITY ASSURANCE
10	DOCUMENTS
11	SAFETY
12	AREA OF APPLICATION

1. INTRODUCTION:

This method statement describes the work procedure to be followed for controlled blasting work on required location at Joy project.

                                   

 

2. SCOPE OF WORK:

 

The scope of work involves the following: Drilling of holes, stemming, filling of explosives, completion and checking of circuit than conduct a controlled blasting operation by covering the circuit by rubber mat.

 

3. REFERENCES AND STANDARD:

This document should be read in conjunction with IS 4081, occupational health and safety act SNS 1996, Blasting safety regulations under section 82 and explosive blasting rules 126 of 2008 and BOCW act for execution of work at site.

4. TOOLS/TACKELS AND MACHINERIES:    

Measuring tape, Tractor mounted Air compressor, Jack hammer, drilling rods, Hose pipe, Nitrate mixture, Electric detonators, short delay detonators, rubber mat, wooden stick, OHM meter, exploder, permanent blasting wire, Explosive van, magazine, storage, transport, and use license.

 

5. MATERIAL AND SPECATIONS FOR BLASTING:

 

 Explosive (nitrate- Make-SOLAR super power 90, 125 grams, dia- 25 mm), detonators ( Make- Solar) and blasting caps etc.

 

v  Depth= 1.50 mtr to 3.00 mtr

v  Hole diameter = 32 mm

v  Cartridge / bulk explosive to charged per hole = as per required or 2 to 5 cartridge approximate

v  Powder factor = 200 GRAMS OR AS PER REQUIREMENT.

v  Weight of Rubber mat shall be 1800 – 2000 kg min

v  No of  Blasting rows = 2 nos

v  Spacing between holes = 1.2 mtr

v  Burden = 1.00 mtr

v  Calculation for powder factor is – PF= Avg 3 nos of cartridge in grams. /  (depth of hole x spacing between holes x burden)  =(125 x 3 ) / (1.5 x 1.2 x 1) = 375/1.8 = 208 grams.

 

6. REQUIERD MANPOWER AND RESPONSIABILITY:

 

Execution Engineer/Supervisor	01 no.
Safety Engineer/Safety Steward	01 no.
Labors (Skilled& Unskilled) (Skilled- Short fire license Holder, tractor driller)	As per requirement

 

a.          Project Manager shall be overall responsible for :

Ø  Safety

Ø  Quality

Ø  Timely completion of the job.

 

b.         Construction Manager shall be responsible for :

Ø  Implementation of Method statement.

Ø  Overall safety, quality & progress.

Ø  Deputing Engineers/Supervisors as per requirement.

Ø  Arranging all required resources to carry out the job and Preparing documents, reports for submission to Consultant/ Client.

 

c.             HSE Manager shall be responsible for :

Ø  All person related to blasting activity shall be inducted by safety person.

Ø  Day to day activity shall be monitored.

Ø  Legal requirements, license, blasting permission shall be checked / verified.

Ø  JSA/HIRA shall be prepared.

 

d          Site Engineers/supervisors shall be responsible for:

Ø  Identify the location for blasting.

Ø  Allotment of resources.

Ø  Compliance with this procedure and relevant project specified requirements.

Ø  Notify to construction managers after completion of blasting activity.

Ø  Coordinating with store, P & M, Safety department.

Ø  Taking safety measure necessary to ensure safety of all personnel involved.

 

e             Site P&M Engineer shall be responsible for:

Ø  Ensuring all machineries in working condition.

Ø  Care shall be taken by the operator of all machineries to avoid any injury to workers.

Ø  Inspection of all machineries shall be done prior to the work.

Ø  Ensuring Proper inspection & maintenance of machineries whenever required or suggest to the vendor.

 

 

 

7.   SHORT NOTE ON BLASTING:

                           Method of blasting includes first step of drilling a number of holes at predetermined angle in a horizontal angle cut pattern or in a vertical angle cut pattern about the central zone of a working face, drilling a number of parallel cut hole within a projective area of the above mentioned slant hole; loading shock tube in the slant holes and an explosive material by indirect priming in the parallel cut holes up to the bottom of the slant holes; blasting the slant holes to form a slant free surface; blasting a center cut hole out of the parallel cut holes to form two free surfaces having a funnel shape; and sequentially blasting a middle cut hole and an outer hole out of the parallel cut holes to form a cubical space

 

Controlled Blasting Services is very proud of its safety record. When using explosives there are three main criteria to consider -
(a)Ground vibration
(b)Fly Rock
(c) Air Blast

 

Surface Blasting Services moves onto site with our drilling equipment. The burdens and spacing of the drill holes will vary according to the depth of the holes and the type of blasting to be done i.e. trenching, road cutting, boulder blasting etc. The holes will be marked by a qualified blaster who will also supervise the drilling. After all the drilling has been done we will obtain blasting and transport permits from the SAPS. We inform the Inspector of Explosives the amount of explosives to be used and the distance from the explosive magazines (place where explosives are stored) to the blast site. The vehicles used to transport explosives have to comply with the specifications set down in the Explosives Act. The vehicles are equipped with 9kg DCP lire extinguishers which are inspected monthly. On the day of the blast, the blaster with his permits, will draw explosives and proceed to the blast site. The explosives are carried in special locked up aluminum boxes. On site the blasting boards will be placed around the blast area. The blaster will then charge up the drilled holes.

GROUND VIBRATION

When blasting close to private property the maximum peak particle velocity is 25mm per second. Example – a house 15 meter from the blast, we are allowed 4.5kg of explosives between each 25mm second relay. One stick of explosives 25 x 200 Energex weighs 0. 11 kg, therefore you are allowed 40.90 sticks between each relay as to be within the limits of 25 mm per second.
By using this method there would be no damage to private property. Should the contractor require a vibro recording to be done, we will employ an independent company to set up monitoring equipment to the nearest house from the blast area. The cost of the vibro is for the contractors account.

FLY ROCK

There are two methods to curtail fly rock. One is by placing rubber blasting mats on the blast area. The other is to place sand on the blast area to a depth left to the discretion of the blaster.

AIR BLAST

The detonating fuse on the surface of the blast detonates at 22000 Feet per second thus causing air blast. The way to curtail the air blast is to cover the surface detonating fuse with sand. Once the blast has been charged up the blaster will then send his staff with red flags to remove all persons and animals to a safe distance. The blaster will then personally visit the flagmen to ensure the area is safe. He will then attach the detonator to the detonating fuse. The blast is set off by an electric shot exploder attached to a blast cable, a safe distance from the blast. The blaster will only fire the shot once he is satisfied that the area is safe and has contact with all his flagmen. Once the shot has been fired the blaster will then visit a blasted area to check that all the shots have gone off. Once he is satisfied he will then declare the area safe. No storage of explosives is permitted on the site.

8. PROCUDURE:

1.       Lineout of co-ordinates/grid lines of respective areas to blasted as per available free face at site.

2.       Study of soil investigation reports & specification received from client.

3.       All underground cables are removed off with respective authorities before planning the blasting work.

4.       Taking out and recording of OGL’s.

5.       All safety procedures and safety checks should be complete before starting the work.

6.       Blasting of area as per given marking by drilling holes with tractor compressor & Jackhammer 

7.       The holes are then charged with nitrate mixture and detonators as per requirement.

8.       The remaining part of the hole is stemmed using sand with the help of wooden stick.

9.       Surface connection of all the holes is conducted and circuit is checked for continuity in presence of Blaster.

10.   The holes will then be covers with a Rubber mat (1800 kg to 2000 kg) and will be loaded with sand bags or tyres for carrying out controlled blasting.

11.   Area evacuation will be carried out before actual blasting is to be carried out with the help of flagman.

12.   The Exploder will be placed at a distance of minimum 10 to 50 mt from blasting location and after clearance from responsible teams / signal man, blasting will be carried out.

13.   Once blasting is carried out immediately after 5-10 minutes area is inspected for misfires and area clearance is given once approved by blaster.

14.   If a misfire occurs the misfire process will be followed to remove the misfire.

15.   Ensure the blasting is proceeding as per given line out and up to required depth or as directed.

16.   Mucking of the blasted material is to be done by attaching a bucket as.

17.   Dewatering is to be done in case of occurrence of ground water.

18.   The working space should be sufficient for labourers to stand and move around in. Safe working conditions should be followed and enforced.

19.   Final cleaning of the excavated surface is tobe done manually.

20.   All required levels are recorded in JMR which is given to the client and contractor representatives before starting the blasting work and at the end of each milestone.

Special care to be taken in case of Misfire

1)     A careful search for cartridges and detonators shall be made in the presence of the shot fire,

Amongst the material brought down by the shot.

2)     As far possible,the search for the detonator and cartridges and the loading of any coal,stone or debris that may contain a detonator,shall be carried out without the aid of tools.

3)     A misfire hole, which cannot be dealt with in the manner so prescribed, shall be securely plugged with a wooden plug.

4)     When a misfire shot is not found or relived, the shot firer shall give information of the failure to  concerned official who may relived or take over charge from him.

5)     The shot firer of the next shifts shall locate and blast the misfired hole after a thorough

Examination of the place, where the misfire was reported to have occurred. If he is satisfied that no misfire has actually occurred may permit drilling.

9. QUALITY ASSURENCE:

·       Assurance of approved methods and materials are being used and conformance of the specifications while execution

·       Inspection and monitoring of work.

·       Incoming material inspection and review certificates.

10. DOCUMENTS:

Ø  Register of Blasting

Ø   Copy of Licenses

Ø  Explosive License

Ø  Transport of Explosive in Road Van

Ø  Shot Firers License

Ø  Annexure 1

Ø  MSDS of following material shall be available in safety department

1) short delay electronic detonator,        

2) super power 90

 

11. SAFTEY:

Controlled blasting  

·       valid competency certificate to carry out blasting

·       Permission of government authority

·       Use of mandatory ppes, Safety shoes, helmet, R jacket, Ear muff/plug, hand gloves, Nose mask, safety goggle etc

·       200 mtr area clear before blasting work

·       Valid compressor & tools tackles third party test certificate

·       Signal manrequired.

·       Close supervision

·       Work during 6.00 am to 6.00 pm

·       Explosive vehicle remove from site after day work completed,

·       Storage of explosive not allowed in  premises

·       Wooden stick use for charging operation

·       Mobile, match box, not allowed while handling of explosive material

·       Fire extinguisher ABC type

·       TBT before start of work and Inspection of blasting hole before & after blasting by competent person with

·       Hard barricades will be provided around the work area in case of deep excavation area and in the area of vehicular movement respectively.

·       Entry to the basement / footing level will be restricted for the access.

·       Vehicular movement will be strictly restricted.

·       Safety sign / Warning sign boards will be provided around the blasting work area.

 

 

12.  AREA OF APPLICATION:

At footing level of all building